Retest Results Research Articles

Validation of the Polish version of the World Health Organization Disability Assessment Schedule (WHODAS 2.0) in an elderly population (60–70 years old)

Purpose. To assess the reliability and validity of the Polish version of the 36-point World Health Organization Disability Assessment Schedule (WHODAS 2.0) in an elderly population. Method. One thousand randomly selected individuals, aged 60–70 years, living in south-eastern Poland were assessed using the Polish version of the WHODAS 2.0. Results. The analysis confirmed the high reliability and validity of the tool. Cronbach’s α index was 0.89. The tool had high stability, and the correlation between test and retest results was high. The relevance of the domain selection was high or very high. A factor analysis confirmed the relevance of assigning questions to domains. High theoretical relevance was also demonstrated. Statistically significant differences between those who were and were not suffering from health problems were observed. An analysis of the internal structure of the WHODAS 2.0 revealed strong correlations between the components of each domain and the final result. Conclusion. The Polish version of the WHODAS 2.0 showed high reliability and validity; thus, it can be used to assess health, functioning and disability in the elderly population of Poland.

Validation of the Italian Quality of Life in Short Stature Youth (QoLISSY) questionnaire

The Quality of Life in Short Stature Youth (QoLISSY) questionnaire is a disease-specific instrument developed to assess health-related quality of life (HrQoL) in children with short stature. While the original instrument was simultaneously developed in five European countries, this study describes the results of the Italian QoLISSY translation, cultural adaptation, and validation. Focus group discussions and a cognitive debriefing process with children (N = 12) diagnosed with growth hormone deficiency or idiopathic short stature and one parent each, as well as parents of younger children (N = 20) were conducted to examine the linguistic and content validity of the Italian version. Psychometric testing was performed using data from the subsequent field- and re-test (N = 32). The results of the qualitative testing of the Italian sample revealed comparability of content to data of the original five European countries. The following field- and re-test results were psychometrically satisfactory including good item and scale operating characteristics, sufficient evidence of reliability, and acceptable evidence of construct validity. In conclusion, the Italian QoLISSY HrQoL-dimensions are comparable to other European countries. The psychometric quality of the Italian QoLISSY version is satisfactory and the instrument is ready for use in Italian patients and their parents.

Discrepancies in central review re-testing of patients with ER-positive and HER2-negative breast cancer in the OPTIMA prelim randomised clinical trial

Background:There is limited data on results of central re-testing of samples from patients with invasive breast cancer categorised in their local hospital laboratories as oestrogen receptor (ER) positive and human epidermal growth factor receptor homologue 2 (HER2) negative.Methods:The Optimal Personalised Treatment of early breast cancer usIng Multiparameter Analysis preliminary study (OPTIMA prelim) was the feasibility phase of a randomised controlled trial to validate the use of multiparameter assay-directed chemotherapy decisions in the UK National Health Service (NHS). Eligibility criteria included ER positivity and HER2 negativity. Central re-testing of receptor status was mandatory.Results:Of the 431 patients tested centrally, discrepant results between central and local laboratory results were identified in only 19 (4.4%; 95% confidence interval 2.5–6.3%) patients (with 21 tumours). On central review, seven patients had cancers that were ER-negative (1.6%) and 13 (3.0%) patients with 15 tumours had HER2-positive disease, including one tumour discrepant for both biomarkers.Conclusions:Central re-testing of receptor status of invasive breast cancers in the UK NHS setting shows a high level of reproducibility in categorising tumours as ER-positive and HER2-negative, and raises questions regarding the cost effectiveness and clinical value of central re-testing in this sub-group of breast cancers in this setting.

Psychometric properties of a Norwegian adaption of the Barratt Impulsiveness Scale-11 in a sample of Parkinson patients, headache patients, and controls.

ObjectiveTo assess the psychometric properties of a Norwegian translation of the Barratt Impulsiveness Scale (BIS‐11) for use in populations of headache, Parkinson's disease (PD), and healthy controls.Materials and MethodsThe BIS‐11 was forward and backward translated by native speakers of both Norwegian and English to give Norwegian BIS‐11 (Nor‐BIS‐11). A convenience sample (110 subjects) of healthy controls (47), PD patients (43), and chronic headache patients (20) (the latter two recruited from a Neurology outpatient clinic), were asked to complete the scale (a subset twice for test–retest). Exploratory and confirmatory factor analyses were done for a single‐factor model, the original three‐factor model and a two‐factor model. Test–retest results were analyzed using the Bland–Altman approach.ResultsThe Nor‐BIS‐11 scale showed good utility and acceptability as well as good test–retest reliability in this sample. Cronbach's α was .68, test–retest bias was −0.73, Cohen's δ = −.134, and limits of agreement were −11.48 to 10.01. The factor structure was found to fit better with a two‐factor model than with the original model with three factors. The model fit indices indicated a moderate fit.ConclusionsThe Nor‐BIS‐11 scale is acceptable and reliable to use in Parkinson's disease patients, chronic headache patients, and healthy controls. The results should be interpreted in a two‐factor model but with caution due to low construct validity. External validity needs to be further tested.

Catch-up validation study of an in vitro skin irritation test method based on an open source reconstructed epidermis (phase I)

We have developed a new in vitro skin irritation test based on an open source reconstructed epidermis (OS-REp) with openly accessible protocols for tissue production and test performance. Due to structural, mechanistic and procedural similarity, a blinded catch-up validation study for skin irritation according to OECD Performance Standards (PS) was conducted in three laboratories to promote regulatory acceptance, with OS-REp models produced at a single production site only. While overall sensitivity and predictive capacity met the PS requirements, overall specificity was only 57%. A thorough analysis of the test results led to the assumption that some of the false-positive classifications could have been evoked by volatile skin-irritating chemicals tested in the same culture plate as the non-irritants falsely predicted as irritants. With GC/MS and biological approaches the cross-contamination effect was confirmed and the experimental set-up adapted accordingly. Retesting of the affected chemicals with the improved experimental set-up and otherwise identical protocol resulted in correct classifications as non-irritants. Taking these re-test results into account, 93% overall sensitivity, 70% specificity and 82% accuracy was achieved, which is in accordance with the OECD PS. A sufficient reliability of the method was indicated by a within-laboratory-reproducibility of 85–95% and a between-laboratory-reproducibility of 90%.

Validation of a questionnaire about the perception of occupational biohazard in Spanish companies

Objectives. The aim of this work was to develop, validate and test a new questionnaire to assess the biological risk in workers with intentional or unintentional exposure to biological agents. Methods. A questionnaire including 34 questions was developed to study the perception of workers against occupational biohazard. Content Validity Index (CVI) and Content Validity Ratio (CVR) were calculated for the analysis of content validity. A pilot study was carried out with 60 workers from 17 companies performing analysis of Cronbach's α to assess the internal consistency or reliability. Results. A total of 518 workers from 51 Spanish companies in which there is exposure to biological agents participated in the study yielding a response rate of 90%. The final questionnaire obtained a Cronbach's α > 0.759 with a stable test–retest result. The questionnaire validation demonstrates that it could be used to evaluate the biological risks and help the prevention of occupational accidents and diseases. Discussion. This study has validated the need to evaluate worker's perception against occupational risks, as well as the application of prevention methods and protective equipment. It is a first step towards developing an occupational biohazards assessment method including all the requirements set by the European Health and Safety Strategy 2013–2020.

Evaluation of the GHRH–arginine retest for young adolescents with childhood-onset GH deficiency

ObjectiveRetesting of adolescents with childhood-onset GH deficiency (GHD) is recommended, but age-related reference data are scarce. We aimed to establish a cut-off value for the GHRH–arginine test (GHRH+ARG) at the typical age of retesting at near-adult height. DesignsWe retrospectively studied 149 patients (108 males) with childhood-onset GHD aged 16.8±1.7years (mean±SD) with a BMI of 20.9±3.5kg/m2 who had received GHRH+ARG in one single center during 8consecutiveyears. Based on the IGF-I serum concentration falling below −2 SDS when off GH, 22 patients suffered from severe GHD of adulthood while 122 were GH sufficient. Five patients could not be determined definitively. GH and IGF-I were measured by in-house RIAs. IGF-I values were transformed into age-related SDS values. ROC-analysis was used to determine the cut-off value. ResultsFor GHRH+ARG, a cut-off limit of 15.9ng/ml had the highest pair of sensitivity (91%) and specificity (88%). GH peaks of the patients with a normal BMI between −1 and 0 SDS were higher than those with a high BMI >1 SDS (p<0.01). ConclusionsWhen retesting adolescents at near-adult height for severe GHD of adulthood, a GH value of <15.9ng/ml in GHRH+ARG is discriminatory with good accuracy. Conversion factors for other GH assays in use are provided. A rational decision for or against the continuation of GH therapy into adulthood can be made based on the clinical history of the patient and the combination of the GHRH+ARG retest result and the IGF-I serum concentrations when off GH.

Reliability of a Simple Method for Determining Salt Taste Detection and Recognition Thresholds.

The aim of this study was to assess the reliability of a rapid analytical method to determine salt taste detection and recognition thresholds based on the ASTM E679 method. Reliability was evaluated according to criterion of temporal stability with a 1-week interval test-retest, with 29 participants. Thresholds were assessed by using the 3-AFC technique with 15 ascending concentrations of salt solution (1-292 mM, 1.5-fold steps) and estimated by 2 approaches: individual (geometric means) and group (graphical) thresholds. The proportion of agreement between the test and retest results was estimated using intraclass coefficient correlations. The detection and recognition thresholds calculated by the geometric mean were 2.8 and 18.6mM at session 1 and 2.3 and 14.5mM at session 2 and according to the graphical approach, 2.7 and 18.6mM at session 1 and 1.7 and 16.3mM at session 2. The proportion of agreement between test and retest for the detection and recognition thresholds was 0.430 (95% CI: 0.080-0.680) and 0.660 (95% CI: 0.400-0.830). This fast and simple method to assess salt taste detection and recognition thresholds demonstrated satisfactory evidence of reliability and it could be useful for large population studies.

The influence of chronic psycho-emotional stress on cognitive function

Aim. The influence of the chronic psycho-emotional stress on the cognitive function was studied.&#x0D; Methods. 160 railroad engineers of main-line locomotives, whose occupation is acknowledged to be one of the most stressful, were examined. 100 healthy volunteers were examined as a control group. A scale of psychological tension PSM-25 was used to evaluate the effect of the stress. Neurohumoral response to stress was studied by the activity of the hypothalamic-pituitary-adrenal axis, defining adrenocorticotropic hormone, cortisol and corticosterone concentrations. Cognitive functions were examined by the neuropsychological tests: Schulte tables, F. Grobov tables, Burdon correction tests. Attention assessment was emphasized due to railroad engineer’s profession specifics. Result. The reaction of the hypothalamic-pituitary-adrenal axis depended on the duration of chronic psycho-emotional stress: resistance period with reduced levels of the stress hormones in the next 5-7 years replaced the period of activation in the first years (with increased production of adrenocorticotropic hormone, cortisol and corticosterone). The reactivation of the hypothalamic-pituitary-adrenal axis occurred after 12-15 years. Neuropsychological tests revealed that the effect of chronic psycho-emotional stress was accompanied by decreased cognitive functions compared to controls. Time for passing the tests and the number of errors increased, productivity, stability and attention concentration dropped. The term of cognitive function disorders onset and their severity depend on chronic psycho-emotional stress duration. The extract of Ginkgo biloba (EGb 761, 240 mg per day for three months) intake has significantly improved the results of neuropsychological retests.&#x0D; Conclusion. Chronic psycho-emotional stress leads to deterioration of cognitive functions, and, in particular, attention. The use of Ginkgo biloba (EGb 761) extract is rational for treatment of cognitive malfunction.

Developing a questionnaire on strategies for increasing housewives’ participation in source separation of municipal solid waste based on the theory of planned behavior

Creating awareness and recognizing behavioral factors associated with recycling is essential for waste management. To identify factors influencing recycling behavior, a theory of planned behavior (TPB)-based questionnaire was designed. The aim of this study was to assess the validity and reliability of the questionnaire. This psychometric study was conducted through a multistage random sampling on 283 homemakers of Mahabad Town, Iran, in 2014. The method recommended by Ajzen and Francis was used for designing the questionnaire. Its validity was evaluated using quantitative and qualitative face validity, ration and content validity index, and qualitative judgment of an expert panel of 8 members and its structural validity using exploratory factor analysis. In addition, its reliability was assessed using internal consistency (Cronbach's alpha coefficient) and retest (intraclass correlation) methods. Of the 53 initial questions, after calculating the content validity ratio (CVR) with values higher than 0.80 and content validity index (CVI) with values higher than 0.79, we modified 3 questions and deleted 8 questions; therefore, 45 questions were approved. Using exploratory factor analysis with a varimax rotation, 9 factors with a value of higher than 1 were selected, which were able to predict 91.81% of the total variation. The reliability of the tool was confirmed through calculating Cronbach's alpha (0.87). Results of retest indicated the consistency of the questionnaire. This research found that the Persian version of the Theory of Planned Behavior Questionnaire (TPB questionnaire) has suitable validity and reliability and can be used in research and administrative activities on increasing the participation of homemakers in municipal solid waste source separation.

The Test-retest Reliability of Korean Standard Language Lists for Schoolchildren in Speech Audiometry

The purpose of this study was to establish the test-retest reliability of language lists for schoolchildren used in speech audiometry including Korean standard bisyllabic word list for schoolchildren (KS-BWL-S), Korean standard monosyllabic word list for schoolchildren (KS-MWL-S) and Korean standard sentence list for schoolchildren (KS-SL-S). Specifically, correlation coefficient, mean, standard deviation (SD), confidence interval (CI) and prediction interval (PI) were calculated for test-retest reliability. Subjects consisted of 31 schoolchildren with normal hearing sensitivity. All lists of KS-BWL-S, KS-MWL-S and KS-SL-S were presented to each subject using CD. Retests were performed in about 2 weeks for most subjects. The results showed fair levels of test-retest reliability for KS-BWL-S, KS-MWL-S and KS-SL-S in speech reception threshold (SRT), word recognition score (WRS) and sentence recognition score (SRS). These results were based on : (1) fair levels of correlation coefficients between test and retest results, (2) insignificant difference between test and retest results, and (3) narrow CIs. However, short version of WRS showed relatively low reliability. Results also demonstrated 95% PI for each score of WRS and SRS. These results can be usefully applied for evaluating individual difference in speech audiometry in various clinical situations.

Improving academic library website accessibility for people with disabilities

Purpose – The purpose of this paper is to explain how Edith Cowan University (ECU) Library improved the accessibility of their web site, aiming for Web Content Accessibility Guidelines (WCAG) version 2.0 Level AA. It describes the results obtained. Design/methodology/approach – Initial testing by consultants was conducted in October 2012. The web site was defined as all webpages which appear part of the library web site, including supplier webpages, plus pages from the university web site and library web site. Library staff applied the recommendations to pages which they could edit, and discussed the recommendations with suppliers to improve their product ' s accessibility. The web site was re-tested in June 2013. Findings – ECU Library web site failed WCAG 2.0 Level A standard in the initial testing and re-testing. Many individual pages which failed initially passed the re-test. The smallest improvement was seen in suppliers’ web sites. Practical implications – This paper could help libraries to improve web site accessibility, as it covers negotiating with suppliers to upgrade their web sites, plus upgrading editable webpages. It shows initial and re-test results, allowing libraries to compare their results to those of ECU. Legislation and guidelines state web sites should be accessible to all users and organisations providing non-accessible web sites risk being sued. Social implications – A web site not complying with WCAG version 2.0 would be very difficult for people with disabilities to access. Upgrading ECU Library ' s web site will provide all users with more equal access to the resources. Originality/value – This study describes problems in upgrading academic library webpages and related supplier web sites and organisation web site to improve accessibility for people with disabilities.

Reliability of the Cooking Task in adults with acquired brain injury

Acquired brain injury (ABI) often leads to deficits in executive functioning (EF) responsible for severe and long-standing disabilities in daily life activities. The Cooking Task is an ecological and valid test of EF involving multi-tasking in a real environment. Given its complex scoring system, it is important to establish the tool's reliability. The objective of the study was to examine the reliability of the Cooking Task (internal consistency, inter-rater and test–retest reliability). A total of 160 patients with ABI (113 men, mean age 37 years, SD = 14.3) were tested using the Cooking Task. For test–retest reliability, patients were assessed by the same rater on two occasions (mean interval 11 days) while two raters independently and simultaneously observed and scored patients' performances to estimate inter-rater reliability. Internal consistency was high for the global scale (Cronbach α = .74). Inter-rater reliability (n = 66) for total errors was also high (ICC = .93), however the test–retest reliability (n = 11) was poor (ICC = .36). In general the Cooking Task appears to be a reliable tool. The low test–retest results were expected given the importance of EF in the performance of novel tasks.

Bayesian approach to guide termination of retrospective retesting after detection of a systematic quality control failure

BackgroundWhen a systematic error is detected in the analytical process, ideally, one seeks to retest only patient samples between the onset of the error and the time the error was detected. In practice, the onset of error is often unknown, and patient samples are retrospectively retested back to the last acceptable QC sample. This can be wasteful of reagents and operator time. MethodsAn alternative approach that is based on the expected number of spurious results is described to determine when retrospective retesting should terminate. Assuming each patient sample was independently measured by an analytical process with an underlying Gaussian distribution, a Bayesian model that takes into account the difference between the original and retest result of each patient sample was developed. ResultsWe are able to significantly reduce the number of samples retested, while ensuring that the average number of spurious results observed under the proposed retesting procedure was similar to or only marginally higher than the baseline number of spurious results when the assay was in control. ConclusionPatient samples measured after the systematic error have high probabilities of being retested under the proposed retesting procedure.

A New Method for Analyzing the Duffy Blood Group Genotype by TaqMan Minor Groove Binding Probes.

Duffy blood group genotyping is useful to ensure transfusion safety and determine the association of Duffy blood group polymorphism with diseases, and therefore has its clinical significance. In order to improve the existing methods for genotyping of Duffy blood group, which normally require post-PCR manipulation, a new method was developed by using 5'-nuclease assay (NA) with TaqMan minor groove binding (MGB) probes. Primers and TaqMan-MGB probes were designed and synthesized to genotype FY*A and FY*B alleles at Duffy blood group locus on a real-time PCR platform. A total of 120 samples were genotyped by using the new 5'-NA and conventional polymerase chain reaction with allele-specific primers (PCR-ASP). The results obtained by the two methods were compared. There was a complete concordance of results for all samples genotyped by 5'-NA and PCR-ASP. The retesting results of 5'-NA were consistent with those of the initial testing. The detection limit of 5'-NA was determined as 100 pg per reaction. The FY*A and FY*B allelic frequencies were 93.3% and 6.7% respectively in the Chinese Han population in Dalian. The 5'-NA for genotyping of Duffy blood group is simple, rapid, reliable, reproducible, sensitive, and high-throughput and is superior to PCR-ASP used in routine genotyping.

한국판 노인불안도구(K-GAI)의 신뢰도와 타당도

Purpose: The purpose of this study was to test the validity and reliability of the Korean version of the Geriatric Anxiety Inventory (K-GAI). Methods: Two hundreds and thirty six elderly were participated to test K-GAI. Goldberg's short screening scale for anxiety was tested for criterion validity. Receiver operating characteristics (ROC) analysis was used for measuring sensitivity and specificity. Results: The obtained internal consistency was 0.88. There were significant associations between test and retest results. K-GAI scores was significantly associated with Goldberg's short screening scale for anxiety (r=.694, p<.001). We found that a score of seven and greater was optimal for a criterion of anxiety among elderly Koreans. At this cut point, sensitivity was 78.9% and specificity was 73.1%. Conclusion: The K-GAI displayed good psychometric properties. This tool would be useful for early detection of anxiety among elderly Koreans with various situations including cognitive disorder, low education, or physical disability.

Assessing medical students' communication skills by the use of standardized patients: emphasizing standardized patients' quality assurance.

The objective structured examination is one of the most valid, reliable, and effective tools for assessing clinical and communication skills, often by use of standard patients (SPs). SPs can also be assessors of those skills. One of the crucial areas when utilizing SP-based assessment is the quality and consistency assurance of their portrayal of the case and their ability to fill in checklists in an adequate way. The aim of this study was to assess the validity and reliability of SPs' ability to assess students' communication skill via a Calgary-Cambridge checklist. This cross-sectional and correlational study was conducted at the Tehran University of Medical Science. We first analyzed validity; the criterion validity of the SPs' filling in the checklists was assessed through determining the correlation between the SPs' completed checklists and the checklists filled in by three physician raters individually and then reproducibility: it was assessed by a test-retest approach inter-rater reliability. The mean correlation for assessing the validity of SPs' completed checklists by individual SPs was 0.81. The inter-rater reliability was calculated by kappa coefficient, and the total correlation among the three raters was 0.85. The reliability of the test-retest approach showed no significant differences between the test and re-test results. The increased number of medical students and different faculties' responsibilities such as doing educational, research, and health services duties assessing medical student communication skills is a complex issue. The results of our study showed that trained SPs can be used as a valid tool to assess medical students' communication skills, which is also more cost effective and reduces work load of medical faculties.

Validity and Reliability of a New Karate-Specific Aerobic Field Test for Karatekas

This study determined the validity and reliability of a new specific field test that was based on the scientific data from the latest research. Seventeen international-level karatekas participated in the study: 14 men (age 24.1 ± 4.6 y, body mass 65.7 ± 10.8 kg) and 3 women (age 19 ± 3.6 y, body mass 54.1 ± 0.9 kg). All performed the new karate-specific test (KST) 2 times (test and retest sessions were carried out on separated occasions 1 wk apart). Thirteen men also performed a laboratory test to assess maximal oxygen uptake (VO2max). Test-retest results showed the KST to be reliable. Peak oxygen uptake (VO(peak)), peak heart rate (HR(peak)), blood lactate concentration, rating of perceived exertion, and time to exhaustion (TE) did not display a difference between the test and the retest. The SEM and ICC for relative and absolute VO(2peak) and TE were <5% and >.90, respectively. Significant correlations were found between VO(2peak) (mL · kg⁻¹ · min⁻¹) and TE measured from the KST (r = .71, 95% CI 0.35-0.88, P < .0001). There was also no significant difference between VO(2peak) measured from the KST and VO(2max) recorded from the cycle-ergometer laboratory test (55.1 ± 4.8 vs 53.2 ± 6.6 mL · kg⁻¹ · min⁻¹, respectively; t = -1.85, df = 12, P = .08, dz = 0.51 [small]). The Bland and Altman analyses reported a mean difference (bias) ± the 95% limits of agreement of 1.9 ± 7.35 mL · kg⁻¹ · min⁻¹. This study showed that the new KST test, with effort patterns replicating real karate combat sessions, can be considered a valid and reliable karate-specific field test for assessing karatekas' endurance fitness.

Identification of Conductive Hearing Loss Using Air Conduction Tests Alone

The primary objective of this study was to determine whether a combination of automatically administered pure-tone audiometry and a tone-in-noise detection task, both delivered via an air conduction (AC) pathway, could reliably and validly predict the presence of a conductive component to the hearing loss. The authors hypothesized that performance on the battery of tests would vary according to hearing loss type. A secondary objective was to evaluate the reliability and validity of a novel automatic audiometry algorithm to assess its suitability for inclusion in the test battery. Participants underwent a series of hearing assessments that were conducted in a randomized order: manual pure-tone air conduction audiometry and bone conduction audiometry; automatic pure-tone air conduction audiometry; and an automatic tone-in-noise detection task. The automatic tests were each administered twice. The ability of the automatic test battery to: (a) predict the presence of an air-bone gap (ABG); and (b) accurately measure AC hearing thresholds was assessed against the results of manual audiometry. Test-retest conditions were compared to determine the reliability of each component of the automatic test battery. Data were collected on 120 ears from normal-hearing and conductive, sensorineural, and mixed hearing-loss subgroups. Performance differences between different types of hearing loss were observed. Ears with a conductive component (conductive and mixed ears) tended to have normal signal to noise ratios (SNR) despite impaired thresholds in quiet, while ears without a conductive component (normal and sensorineural ears) demonstrated, on average, an increasing relationship between their thresholds in quiet and their achieved SNR. Using the relationship between these two measures among ears with no conductive component as a benchmark, the likelihood that an ear has a conductive component can be estimated based on the deviation from this benchmark. The sensitivity and specificity of the test battery vary depending on the size of this deviation, but increase with increasing ABG size, with decreasing test frequency, and when results from multiple test frequencies are taken into account. The individual automatic tests comprising the battery were found to be reliable and valid, with strong, significant correlations between the test and retest results (r = 0.81 to 0.99; p < 0.0001) and between automatic and manual audiometry procedures (r = 0.98 to 0.99; p < 0.0001). The presence of an ABG can be predicted with a reasonably high degree of accuracy using AC tests alone. Applications of such a test battery include any clinical context in which bone conduction audiometry or specialized diagnostic equipment is unavailable or impractical. Examples of these include self-fitting hearing aids, whose efficacy relies on the ability of the device to automatically administer an in situ hearing test; self-administered adult hearing screenings in both clinical and home environments; large-scale industrial hearing conservation programs; and test environments in which ambient noise levels exceed the maximum permissible levels for unoccluded ears.

Reliability of self-administered Work Ability Index questionnaire among Korean workers

Although the Work Ability Index (WAI) has been used in many countries, its reliability is yet to be validated in Korea. In our study, test–retest results of WAI total score, WAI category and seven subscales were compared. The correlation coefficients of WAI total score and subscales 1 and 2 between test and retest were 0.70, 0.80 and 0.63, respectively. The κ values on WAI category, subscales 4, 5, 6 and 7 were 0.52, 0.32, 0.31, 0.48 and 0.85, respectively. The results of our reliability test show that WAI scores of female, younger and private company workers were found to be higher than those of male, older and public company workers, respectively. We conclude that overall test–retest reliability of WAI in Korea is acceptable. Another notable observation from our study is that work ability dimension (subscales 1, 2 and 7) had a higher reliability, whereas health dimension (subscales 3–6) had a lower reliability.